Electric water-heater.



l. LETlH ELECTRIC WATER HEATER.

APPLxcATmN man 1uLY6,1915.

v Patented Dec. 26, 1916.

UNITED ASTATES PATENT OFFICE.

JAMES C. LEITCH, OF LOS ANGELES, CALIFORNIA.

ELECTRIC W'ATER-IIEATER.

Application filed July 6, 1915.

T0 all whom it may concern.'

Be it known that I, JAMES C. LinTcH, a citizen of the United States, residing at Los Angeles, in the county of Los .-Xngeles and State of California, have invented new and useful Improvements in Electric later- Heaters, ot'which the following is a specification. l

My invention relates to electric heaters and more particularly to that class of heaters known as immersion heaters.

It is an object of my invention to providean electric heater which is portable and may be handled while electrically connected, without danger to the operator.

JAnother object of my invention is to provide an electric heater for liquids which depends upon the conductive qualities of the liquid in which it is immersed to complete the electric circuit, so that there will be no heat generated within the heating elements when .the heater is withdrawn from the liquid.

Another object is to provide an immersion electric heater which embodies a spiral or helical inner conductor and an outer conducting heliX insulated from the inner helix and forming spiral openings in the helices to permit the free circulation of' the liquid to and from the opposite sides of the helices.

It is a further object to provide a liquid heater ot' the class described in which the heating' element will be entirely exposed 'Lo the liquid and will at the same time be so constructed that a short circuit-is not likely to occur due to foreign substances connecting the two poles of the heating element.

My invent-ion is illustrated in the accompanying drawings in which: l

Figure 1 is a perspective view illustrating' the application of my invention as applied in heating liquid. Fig. 2 is a View of the heater in side elevation. Fig. 3 is a view in verticalsection of a modification as seen on the line 3-3 ot' Fig. 2 and shows the outer spiral element and the inner spiral element as being wound in opposite directions. Fig. 4 is a section in plan on the lines 44 of Fig. 2.

More specifically, 10 4is a screw plug which consists of the dielectric body member 11 mounted within the. end of a metallic threaded sleeve member 14 adapted to engage complementary threads within the socket 15 through lwhich electric current is supplied to the contact vmember 12 and the Specification of Letters Patent.

Patented Dec. 26, 1916.

seriai No. 38,042. i

screw member 14 from electrical supply conduits 1G and 17. The lower end of body member 11 is enlarged as shown at 1S and has secured, by screw 19. to the outer periphery thereof, the end 20 ot' a lielically wound conducting member 21; the opposite end 22 of which is secured to the outer circumference of an insulating base member 2l by a screw 23. Secured to the inner face 25 of the base 24 by a screw 2G, is the end 2T of an inner helically wound conducting member 2S which projects into a counterboi-e 29 in the body nieniber 11; end 30 of said conducting member being secured to the contact member 12 by a screw 31.

The conducting member 21 is preferably formed of a ribbon of sheet metal with coils of equal diameter so as to conform to a cylinder; the coils being of a width greatly in excess ot' the width of the spaces therebetween, but which spaces are siificiently wide to permit the ready How of liquid therethrough. The coil 28 is also preferably formed of a ribbon ot' sheet metal of a narrower width than the ribbon of which the coil 21 is formed and is wound to form a number of coils of equal diameter having broad outer faces extending concentric with and parallel to the inner faces of the coil 21, and spaced therefrom to form a gap.

The' coils 21 and 28 being insulated from each other by the end members 11 and 24, no current can pass therethrough when they are connected to a source of electrical supply, unless the coils be submerged in a liquid. By this arrangement, the device .will operate to perform its heating function only when immersed, and will therebyp'er'mit its being handled without danger of shock when not submerged; immersion of the device in a liquid operating to complete a circuit through the coils and withdrawing it from vtion between the coils 21 and 28.

as a conductor to complete electrical connec- The llow of current through the device will then be as follows: from socket 15 through the contact member 12 to theinner coil 2S,thence through the liquid to the coil 2l, from whence it returns through the conducting member 32 secured to the upperend of the coilQl by a screw 33 and completing connection with the socket l5 through the threaded sleeve 14. The current passing through the liquid operates to heat same. lVhen the desired temperature of the liquid has been obtained, the device is withdrawn therefrom, thereby automaticall)Y breaking the `How ot' current through the coils. Y-

l. In an immersion electric heating device, the combination ot' an innerfhelical electrode and an outer helical electrode concentric with said inner electrode and dielectric-all)T mounted therefrom, the space intervening between the convolutions ot the material from which the electrodes are formed being open and less than the width otl said material between the spaces.

2. In an immersion electric heating device, the combination ot' an inner helical electrode, an outer helical electrode concentric with said inner electrode, an electrical contact plug secured to one end 'ot' each of said electrodes, and a dielectric base secured to the opposite ends olg said electrodes, said inner and outer electrodes being composed ot metallic ribbon, the width of which is greater' than the space between the convolutions thereof, the spaces between said convolutions being open.

3. In an immersion electric heating device, the combination ot' an inner electrode of helical form, an outer electrode ot' the saine form encompassing said inner electrode and spaced therefrom, the spaces between t/he eonvolutions of said helices being open, electrical connections secured to one end of each ot' said electrodes, and an insulating` base securing the opposite ends of the electrodes.

4. In an electric heating device, the combination of an inner cylindrical electrode and an outer cylindrical electrode encompassing and insulated from the inner electrode, said cylindrical electrodes heilig formed with a helical opening extending the length thereof, and means whereby the inner and outer electrodes may be electrically connected.

5. A water heating device comprising an inner conducting helix and an outer electric conducting helix encircling the inner helix concentric therewith and insulated therefrom, having the spaces between its coils open to permit the passage ot fluid therethrough- 6. A water heating' device comprising an inner conducting helix havingthe spaces between its coils open, and an' outer electric conducting helix encircling the inner helix concentric therewith and insulated therefrom, having` the spaces between its coils open to permit the passage olf tluid therethrough.

7. A water heat` helix being greater than the widths ofthe coils ot the inner helix to position the spaces between the coils of the helices out of alinement with each other.

In testimony whereof ll'have signed my name to this specification.r

JAMES o. LEiTcH.

ing device Comprising an,` inner conducting helix and an outer electric 

